The Swiss-based organization returned to the port city with its information and communication technology (ICT) event, following ITU Telecom Asia 2004 and the ITU Plenipotentiary Conference in 2014.

However, this year it did not live up to its billing as a leading exhibition and forum for the global ICT industry.

The telecom fair failed to draw public attention as evidenced that the spacious Busan Exhibition and Convention Center (BEXCO) was not crowded at all. Many of participants, who had few opportunities to demonstrate their technologies, were spotted keeping their eyes on their smartphones.

"We expected many people to visit this event, but there were fewer visitors during the four days," said an official of an African exhibition booth, who also participated in last year's fair in Bangkok, Thailand. "There were quite a few people from overseas last year."

He added that the relatively few connecting flights to Busan prevented foreign visitors from attending.

"If it had been held in Seoul, many more people could have visited," he said.

People in the nation's second-largest city had a lukewarm attitude toward the event, as well.

"I did not know that the ITU Telecom World was taking place at BEXCO. Many other Busan citizens wouldn't know it, either," said a 39-year-old housewife, who declined to be named.

She suspected the Busan city government did not do its best to promote the event.

"Unlike other large-scale exhibitions such as a motor show and a baby fair, I hardly saw any advertisements about the event," she said.

She also asked why the event was held during weekdays, which made it tougher to attend.

Even a cab driver who is usually familiar with what is happening in the city, did not know that the fair was being held.

Asked if people here had interest in the event, he answered bluntly, "What is it?"

Amid the lukewarm interest, Busan allowed high school and university students in the region to attend the fair for free for the final two days, but exhibitors were busy packing up Thursday morning, with some already gone.

A lack of high-profile companies at the telecom fair was another reason for little attention.

According to the ITU, more than 500 companies participated in this year's event. But few top Korean companies attended.

The exhibition failed to invite globally renowned information and communication technology players. The remaining booths were filled by small- and mid-sized companies.